Hyquip Fault Finder   Lack of Delivery Lack of Pressure Excessive System Noise Causes of Pump Failure Irregular Cylinder Action Excessive Fluid Temperature Lack of Delivery ▲Top   Cause   Remedy   Incorrect rotation of pump   Reverse immediately   Oil level in reservoir too low   Top up with correct filtered fluid   Loose suction line connection   Check/tighten pipe fittings   Suction pipe or strainer blocked   Clean if possible or replace   Incorrect viscosity of fluid   Check with pump makers specifications   Air breather blocked   Check and clear   Pump parts broken   Replace or repair if possible   Relief valve jammed open   Clean and adjust valve, replace if neccesary   Pump speed to low   Check speed with makers modifications   Loss of accumulator precharge   Check pressure against design specification   Incomplete valve action   Isolate valve and check operation   Incorrect assembly, broken drive coupling   Rectify   Incorrect pump setting   Check and adjust if possible   Blocked filter   Clean if possible or replace Lack of Pressure ▲Top   Cause   Remedy   Is there a lack of delivery   Check with Lack of Delivery chart   Relief valve set too low   Isolate system and check relief valve   Relief valve held open   Clean and adjust valve   Is oil returning to tank through a valve   Check valve operation   Are valves leaking internally   Isolate valves and check operation   Are there any external leaks   Tighten fittings and check components   Normally closed valves stuck open   Clean and check system for contamination   Is pump casing loose   Tighten case to correct torque   Are any oil line pipes blocked   Clear blockage   Incorrect assembly, broken drive coupling   Rectify   Pump failure due to fatigue, contamination, pressure overload, etc.   Check pump and repair if possible, if not replace the pump Excessive System Noise ▲Top   Cause   Remedy   Suction line or strainer blocked   Clean if possible or replace   Aeration in suction line   Check/tighten pipe fittings   Is pump casing loose   Tighten case to correct torque   Restriction in pump passages   Check and clear obstruction   Trapped air in fluid   Check components, tighten pipe fittings, bleed system if neccessary   Breather blocked   Check and clear   Pump speed excessive   Check speed with makers recommendations   Incorrect viscosity of fluid   Check ambient conditions and design specification   Misalignment of drive coupling   Re-align   Filter too small   Check flow and pressure drop   Faulty sticking valve   Isolate valve and check operation, replace or repair if possible   Accumulator surges   Check accumulator precharge and correct functioning of loading valve   Loose return pipes under tank lid   Check/tighten pipe fittings   Pipework too small   Check with design specification   Intermittent electrical supply   Check for correct supply Causes of Pump Failure ▲Top   Cause   Remedy   Excessive pressure   Check relief valve setting   Seizure due to lack of fluid   See Lack of Delivery chart   Dirt wedged in clearances   Check filters and fluid condition   Fracture of body due to pressure overload   Check relief valve setting   Pressure surges   Check accumulator precharge, valve settings, load and circuit design   Failure of control valves   Replace or repair valve   Cavitation aeration   Check fluid lines to tank and suction pipe   Dirt materials in fluid   Check filter and fluid condition   Incorrect viscosity of fluid   Check temperature and viscosity with design specification   Excessive pressure over-rated   Check relief valve setting   Misalignment of drive coupling   Re-align   Intensification fluctuating load causing reverse flow   Check load against design specification and correct functioning of valves Irregular Cylinder Action ▲Top   Cause   Remedy   Is there air in the system   Check/tighten pipe fittings, bleed if neccessary   Cylinder misalignment   Check and adjust   Heavy load at slow feeds   Slides require lubrication   Hose burst valve sticking   Clean, adjust or replace if neccessary   Bent piston rod   Replace with new and reseal cylinder if neccesary   Over centre load   Fit a load control valve   Incorrect valve setting   Isolate valve and check operation, adjust if neccessary Excessive Fluid Temperature ▲Top   Cause   Remedy   Incorrect viscosity of fluid   Replace with oil of correct viscosity   High ambient temperature   Check fluid temperature around system   Worn pump   Replace   Failure of the cooler   Repair or replace   Oil level in reservoir to low   Top up with correct filtered fluid   Insufficient ventilation of power unit   Check position of power unit and move if neccessary   Incorrect relief valve setting   Isolate valve and check operation, adjust if neccessary